Multiple stage cementing



jaar/@y C. A. PlTTS MULTIPLE STAGE CEMENTING Filed June 5, 1944 Jan. 27, 1948.

Jan. 27, 1948. c. A. PIT-rs MULTIPLE STAGE CEMENTING Filed June 5', 1944 2 Sheets-Sheet 2 Patented Jan. 27, 1948 man .. I(JharlesA.Bitte Duncan, Okla assignorto Halliyburtoil Well .Clementine Company, Duncan,

.Applicationalune 5; 1944, :Serial Nor-.5383848 (Cl. "16d-1) ""'31Clams. 1:1 This invention. relates. to .the cementing irof v1 oil wells and more particularly toad-arrangement for c ementing', long strings otticasing ein .stages so that .the Acement .which vfills-the annular .space around the casingmay ybesupplied thereto Wthf out all oi it passingfaround ,the bottom-1off-the casing.' The multiple .stage cementing of wells is now well known r.to.those,ski11ed.in.the.aart. Methods andapparatus for yaccoinplishing this are disclosed ,in .-the.. .United ..States patentl .to Halliburton, :Reissue y lxlofli'it egranfledf :May 14,11935.

In .theniultiple `stage:eementing, of wells, a valve structure, usuallynalled .themultiple :stage unit. is .madelun withthecasing..ilhelarraneea mentis `such that, at ',theproper time, .the-,.valve in` the unit` is Qllenedso (thatacementlgcaneflow outwardly therethrough .into .the annu-lar A:space around the casing. The valve may be aasleeve valve, as .it is init :the -above,mentioned` reissue patent to` Halliburtomandthe sleeve-,may `,be moved toi open` position ,by ioneiof ,therementing plugs used in thecementingioperation,

.It is very importantjn.. carryinggon .multiple stage cementing V` operations, -to,provide some means for sealing ltheportslin f them-,ultiple lstage unit vafter the cementisadischarged therethrough. In the reissue patentto Halliburton. `Cji'dcabove, poppet valves actuated by leaf springs areprovided on the outside vkof` the, ,unit :to accomplish this purpose. AAniotlien typeof .vali/e,A also-spring actuated, is Vdiseldsd. inl `the patent,to,..0wsley et al1; No; '2,201;299grantedMay Y21;, V1940. .Y The use 'of springs -for` actuating gpoppet-,Valves or other valves Von the outside .ofthe multiple stagel unit is. not entirely satisfactory. There isdanger that thefsprings .may be .brokennorathe valves damaged as the casingis-lowered ,into the Well, and there `is danger thatsomenbstruction may lodge in the ports andepreilentthe:Nalvesseating properly.Y Ifthe-valvesdo.-notseatiproperlyfzafter the well -is completed Water may-:seep along the cementA :and-enter thatcasingathroughithe ,ports of :the multiplerstagef-unit. :1f ome operators eprefer-to :pump thef'cementcaroundzthe ent-ire string of casing rather: Mthan use ithefmultiple stage ceinenting. :process: Ebecause of the lislangers mentioned above.

It is an object of the present inventionto'mtovide Yay multiple Astage#cement/ing unit in.. which sleeve `valves -arewprpvided both *foronening and for closing the portsjthrough which the .cement is discharged and in which the isleeves-.arefpositively actuatedyby thedocumentingililllgs .us,edfili 2 carrying.. on *the multiple stagev cementing operation.

Otheriobjects andzadvantages reside `in certain novel Afeatures of the varrangement .and yconstruction of parts ,as ,will ,be .apparent from the :ollowing description taken in ,connection with the :accompanying drawings, in which Y Figure v1 .isa verticalcross-sectional viewjoi an oil Well with 'casing therein, the casing being provided with a mu1tiplestage cementing unitcon- Structedin,accordancewith the principles vof the invention, the View. alsoshowinga body of cement being pumped intoY the casing `with two cementing plugs capableofucooperating With-the multiple ,stage cementing `unit to. actuate the same;

' "..FgureZ is anenlarged vertical `cross-sectional view'oi the multiple Stage cementing unit oiFigure 1 andfjllustratingthe. position o f the Vparts before. either' of the Vplugs enters the Vmultiple Stage unit:

Vldigure 3 is va transverse cross-.sectional View.v of the multiple stage unit taken o n the line 3-'-3 of Figure;

Figure 451s a vertical crossfsectionalview of the multiple Astage unit' of Figure 2, showing the position of, the parts after .the rst or lower cementing plug has performed ,its function in the multiple'stage unit butprior tothe time that theisecond or upper cementing plug has reached the unit, this view illustratingr the position `of .the parts'ascementis being discharged through the ports of themultiplestage,.unit; and

Figure 5 is a vertical cross-,sectional View of thei'multiple `stage'unit of Figures 2 and 4 and illustrating the position of-'the parts after both cementingfplugs have `performed their function in'the multiple stage'unit andshowing the position 'of thevparts as they exist after the cement hasbeen discharged from the multiple stage unit. y@Referringlto the'fdrawings in detail, and .rst to the-arrangementfof Figure 1, it will be seen thata bore hole is there illustrated at I l. Withinnthe hole there isa casing 12in which is incorporated -a multiple lstage unit constructed in accordance with the principles of the present invention, together -With a guide shoe I3, and a oat valveM.

@The :multiple-'stage unit isshown in detail in Figures y2 to 5. AIt includes an elongated collar EB-internally threaded at-its upper end, as illustrated air-IEytomakefeonnection with the casing, andiinternally. tfhreadedzat-its vlower end, as mustratedfat 11,.,-.to lmake connection with ashort coupling .I. 8, v`which vis screw-threaded -into one kof the regular oollarsaliloiitheteasing.- Itv will-be seen that in the arrangement illustrated the internal diameter of the coupling I8 is the same as the internal diameter of the casing, and that the outer diameter of the elongated collar I of the multiple stage unit is somewhat greater than the outer diameter of the regular casing collars I9.

The elongated collar I5 is provided with cement discharge ports 2|. Sleeves are provided on the interior of the collar I5 for controlling the passage of the fluid through these ports. The lower of these sleeves is designated 22, and when the device is made up with the casing and lowered into the well this sleeve covers the ports and prevents the passage of iiuid therethrough. The sleeve 22 may be held in the position shown in Figure 2 by three shear pins 23 in the collar I5 as illustrated in Figure 3. It may also be pro-V vided with three vertically extended guide slots 24 to cooperate with the guide pins 25 in the collar I5. At its lower end the sleeve 22 is provided with a ring 26 made of drillable material such as Bakelita this being positively. secured to the sleeve 22 by an annular nut 21. The inner surface of the ring 26 is tapered to provide a seat as illustrated at 28. The bottom edge of the sleeve 22 is provided with a slot 29 while the top edge of the coupling I8 is provided with a lug 3D so that when the sleeve 29 is moved downwardly to the position shown in Figures 4 and 5, the sleeve 22 cannot then be rotated with respect to the casing even though the guide pins 25 should shear. It will be seen that the outer surface of the sleeve 20 is cylindrical and that it nts snugly within the collar I5. Two packing glands are provided on the outside of the sleeve 22, those near the top being designated 3I and the lower ones being designated 32. Thus, when the sleeve 22 is in the position shown in Figure 2, an effective seal is maintained to prevent the passage of fluid through the ports 2I, and when the sleeve 22 is in the position shown in Figure 5, there can be no ilow of uid between the sleeve 22 and the collar I5 at a point beneath the ports The interior of the sleeve 22 may be provided with a tapered surface as illustrated at 33. Above the taper additional packing is provided as illustrated at 34, for the purpose of effecting a seal with the skirt of the upper sleeve 35 of the multiple stage unit.

The upper sleeve 35 is held in the position shown in Figure 2, while the multiple stage unit is made up with the casing and lowered int-o the well, by means of one or more shear pins 36. This sleeve may be provided with a guide slot 31 cooperating with a guide pin 38 fixed to the collar I5. The main portion 39 of the upper sleeve 35 is of the same outside diameter as that of the lower sleeve 22. At its upper portion, however, the sleeve 35 is of reduced outside diameter and is provided at its upper end with a split latch ring 40. It will be seen that the collar I5 has two diameters. As shownin Figure 2, the upper portion of the collar I5 has an internal diameter the same size as the outside diameter of the upper portion of the sleeve 35, but from a point just above the pin 38 on down, the inside diameter of the collar I5 is slightly larger. This provides a shoulder 4I inside the collar I5. When the sleeve 35 is moved downwardly to the position shown in Figure 5 the latch ring 4!! expands beneath the shoulder 4I and prevents upward movement of both sleeves 22 and 35` l The portion 39 of the upper sleeve 35 is provided with packing 42, which eiects a seal with the interior of the collar i5. This seal is of no importance when the sleeve is in the position shown' in Figure 2, but when the sleeve 35 is moved to the position shown in Figure 5 the packing 42 then functions to prevent ow of iluid through the ports 2l, and upwardly between the sleeve 35 Vand the interior of the collar I5.

The lower portion of the sleeve 35 is provided with a skirt 43 of reduced outside diameter. The

' lower edge of the skirt may be slightly tapered as illustrated, the angle of the taper being about the same asthat on the surface 33 of the lower sleeve 22. It is desirable that the upper edge of the lower ring 22 be provided with a lug shown `in dotted lines at 44, and that the lower edge of the-portion 39 of the sleeve 35, outside of and above the skirt 43, be provided with a recess as shown in dotted lines at 45 to cooperate with the lug 44 to prevent rotation of the sleeves 22 and 35 relative to each other after they have been telescoped together as illustrated in Figure 5. If such an arrangement is provided when the parts are in the position shown in Figure 5, neither sleeve 22 nor sleeve 35 can be rotated with respect to the casing. The purpose in providing means for preventing rotation of the sleeves 22 and 35, is to prevent damage thereto, or to the packing around and between them, when cement is being drilled out of the interior of the multiple stage unit. It will be observed that the internal diameter of the sleeve 35 is the same as the internal diameter of the casing I2. Likewise the internal diameter of the sleeve 22 at the thickest portion thereof is the same as the internal diameter of the casing, Hence these sleeves are not drilled out after the cementing operations are completed.

To provide means for shearing the pins 36 and for forcing the upper sleeve downwardly at the desired time, a ring 46, made of drillable material such as Bakelite is provided in the multiple stageunit. In the arrangement shown, this ring rests loosely upon the upper edge of the sleeve 35. Ring 46 is provided with a seat 41 adapted to receive and form a tight seal with the lower portion of the second or upper cementing plug.

The cementing plugs used in connection with the multiple stage unit of the present invention need not differ materially from those heretofore used in carrying out multiple stage cementing operations, except that care must be exercised in the selection of the proper dimensions to cause the first or lower cementing plug to passthrough the ring 46 to seat and maintain a seal on the lower ring 26, while the second or upper cementingplug must seat and maintain a seal on the upper ring 46.

The rst or lower cementing plug is illustrated in the drawing at 48. As shown, it is constructed of a cylinder of wood to which is attached at the lower end one or more exible disks ofbelting or the like, as shown at 50, while at the top a tapered valve portion 5I is provided to maintain a seal with the seat 28 of the ring 26. Above the valve portion 5| additional belting 52 may be secured.

The second or upper cementing plug is shown in the drawing at 53. It also may be constructed of a cylindrical body of wood with disks of belting at the top and bottomas shown at 55 and 56. In this case the tapered 'valve portion 57 which maintains a seal with the cooperating ring spermine uppeiefilexiblelalisk" 'butheeaphigff #aanname aroundntheefskirtrflls romzdthespacenwithinthee iblerrzupz'5'8enayebeisprrmidded; sleeizesafanct.sinceztheifslurry .is substantially-i Theoperaticnu'of thefnmltiplie stageunitiillus-i'e compres'sblte theriplugzlrcan not-.innove downs trat-ediisaszfollowstsp.. .ewardlyzanyrfurthenni(Note thatflin Figure 5,:=theff With' the'fpartsiiirithpositiorrshumnfimii'igureee plugiiis-:not restinginnxthe ring 4.50,. The sleevess" 2sthe zmrltipleisfstagesunit;iismaderupii'witha th 2 ziandaSErareso iconstructedl' andfarrangediwith casing] 2`andilcwere'df1into; ther Wella flnraccordei res-p'eetttoffthe.;ports` :2| "that, sucht-:relative: fluide. Y.; ancer-withitheeusua'lfpracticeimud'zis'i them-.'circuee pressllxresarebdeveloped:assto cause the sleeve 'f3 5 s f l lated: downwardly-:through the fcasingul2 laindzfup ldt'ltofmdve onsdownwardlye'to athef:inalf-fpositiorrrs. wardlyrzethrouglfr;'fthe,:arnflulars'sspacer@ Thezinrst shown in Figure 5, oncefthezpressureonfthe:plug-.1? stagezofgemenmslurryisthenzmixedrarrdspumpied 53vfhasrliausedathefskirtrrleso effectefa :seal:l with into?thermellrethissbo'dseoizslurmmowingidownn the sleevezztasdescribed above;v lItewill;befseena: wardlyrithrouglttheeshoeifl:ligotrthexcasin and thatsvvhen" the-pldlgsaare i'nathevpositionlshown'f up around the lower portion thereof. Thisifrlrst LlgginwFignrel;iiexceptfonliyariationsiduestokflowrm stageefislurrywis.rollowedeby aameasuredaquane` the ud pressureabovethefplugaais the same tityfofemudfsomwatem Therfsecondestagefoli-:slurry n as that below the plug 53, and the same asrthat isaehempum-peieintoethewwellabehmdrthe. firs' outside of..-the.\multiple:stage funitii'. Whensthe orfilower plugf 48er This ssecond=z1stageiis for skirt-'4Seeiectswits-initialvsealewiththe 1lower-- lowedffbyfthe;secondaorfbupperrphlg 3: el Asath Sggsleeve 2 Zeta difference ein .luid.,pressures kis rthen-j plugs :485mm Wit-l1therv body eoecerrrentisluri set upabetweensthe` `interior/and exterior` of .the f therebetween#passedewnwardln nt'oxthe wellmt'h multipleistage--unit; u From: that point7 on; fluiclv 1' nrs-t yorf lowerf plugf enters-fthe? multiple-:stagnni can- :.notfow --tlrirough:the-sports 2 I` andY 'the' ex; andseatsLupemthesringf 2st f The':pump:pressur ter-ier ofthecasingiisnotfsubectedftoV pump 'prese-W thenUshea-rs thewpins andsthewlower ring! 125g-:1,sures-I Thezeuidtpressuref-beneath.thewplugs'L passes :Ldown'wa'rdl .unti1eit=irestszi-:upon'the o thenwbecomesfequaltomhatfabovefit and thel plug/ff. @father Coupling l 8, TheifpaptSr-aareethen "iniftlrerr:A 53v-stopsemovfinge.. I-Iowever-,fdue".to.theA particular-- positiona shown sin: Figuren@ e.. With theipartsemtficonstruction-Mhe sleeves-f2 2-v and' -3 5,- =thediierminpunt-,inmune.-.Seoonft'stageaofecemem;eflow enceeirr:fluirie-.pressure-Abetweenl thefdnside and outwardlyfthroughthepilrtsrfzl offthe-imultipleaetoutsideeotetheecollan' l5.causes .theusleeve'351to stageffunit. move ontdownftoe-itsfinal fpositioni-.fz AV downward-1:,

After mostfofethecementf slurryhasfdischargeda; forcee. en lualrtn` thee difference fine the. ifluid. plies fr through-theeports-z Isthe seconder uppercemgent surerinsdeands,outsidethef collar i|5-,-times\fthe1r; ingaplug53oomesltoz `rest. upon-,theriIl-gra :Thi areafof.y the annular .zspacemequali tofthe,` :area ofte'V causes the pins :36ste Ksheareande. the tuppers-slew Ertheiupperfedge; ofetheffsleeve 122-.: is s exerted :upon 35ftomove downwardlyl';y LThe:parterthenetaketh thefsleeve 3 5 at-this -vtirr1er-r This forcer- :added to position, shownnfpifgure-N.11; Wmubesgen thats... the .momentum'fimparted-` to -thesleeve 35 upon. inEigu1re-:5 .theaskirtwM-l :ofmsleevemhgs i'jeilel-ca the--^5ha1il-ng Of ether 1li-IlS3-dliVeS'tl'let'SlBeVe`35`I scopedintoethe lowersleevevzaan'd that l-ishelatehr. intoftightfwedging engagementiwithtthe taperedi ring 40. hasexpanded beneaththeshould-c1124!i-=40ll30ri 9nf33e0fes1eve'f27n Tilman-,$.21 argipermanentiyseald beause there lili-"ginth'sldescripton-it:will:bevclear:tofthosefe latch ring 43 preventsupward movement of eithen' Skilledv in the aft that the Sleeves 22 and 35 DIO sleeveszaegr 35gandetheavarious paeking preventvideswhaamaysbe.referredltaas a differential ing leakage. After the cement has hardened the valv'r.. That.is,these-sleeves functionto i-coverv-v plugs 48 and 5371mgetherfwitlntlerngs 26 and 45.',pr`11ncever the dischargeeportsr-in-the collar-'fins-- 46 and the small body of cement fwithin the IeSpOnSa-tU-flud-pressureconditionsexistingcinff multiple stage unit remaining'btween tleplugstheVv cellar.Y creto .thedierentia1-- pressure-existingif 48 and 53, is drilled out, leaving"the'`interior"' attimes=between-tlieinterionandexterioroftheirof the multiplstagefunitlclearaandinobstructed. collars'. i y

In constructing a multiple stage unit n,.,.ac.- 501;, The'1 difli'rentiaLpressure between'theflinterlor iA cordarcewithxhe principles ofithepresentsinvena andgexterior. .cfrV theflcollarA at!y the time when the' .I ti'ny'care must be" exereis'edftd previde lfor" thA skirt f .the upper` sleeve is Just tesi-rulingitsiteleeA escape ofld' frin-,lcertainlportihs of theEap-` scopicQmovement-intothe..lower sleeve Vis instru-- paratustoperr'n'it' the" desired' telescopic;actierifl mental in eausing theuppersleeve35 to. movefon` offtne sleveszznnd'a' Y 55downliathrandwefiecta permanentseal loe-w Attenti'on's'called'to'thefatth'at after' th' tvv-een a point above the ports and the lower pins 23 have sheared the lower sleeve 22 which sleeve 22. Since the lower sleeve is then below is then in the position shown in Figure 4, takes the ports, the ports are permanently covered.

such a position that the upper edge of the sleeve It will be apparent to those skilled in the art is ush with or just beneath the ports 2l. Thus that the principles of the present invention may no fluid is trapped in the small annular space outbe carried out in a variety of ways. Devices side the skirt 43 and within the collar I5 as the other than the sleeves may be used to cover and sleeve 35 moves down to its nal position shown uncover the ports. Various means other than in Figure 5. the shear pins may be used for holding the When the upper cementing plug 53 comes into o5 sleeves temporarily against sliding movement so engagement with the ring 46, the fluid pressure that they may be successively released to pershears the pins 36 and forces the upper sleeve form the intended action of controlling the ow 35 downwardly a short distance, i. e. the disof fluid through the ports. Inlieu of the cementtance necessary to cause the skirt 43 of this sleeve ing plugs shown and described herein for actuatjust to enter the upper portion of the lower o ing the sleeves, other objects such as balls may sleeve 22, and effect a seal with the packing 34 be caused to pass down through the casing. on the interior of the sleeve 22. This completes Furthermore, it will be apparent that the inthe function of the plug 53, but at this instant vention is not confined to the use with cement the telescoping action'of the sleeves 22 and 35 but may be employed in any case Where it is is not completed. As soon as the 'initial seal '(5 desired to limit the amount of ud which is t0 flow through the ports by passing two objects successively down the casing. Packing rings of various kinds may be used instead of those particularly illustrated in the drawing. In the appended claims where the Words "normally or normal position are employed in connection with the position of the sleeves or other devices which cover and uncover the ports, it will be understood that this has reference to the position of the parts as the multiple stage unit is being lowered into the well.

Thus, while only one embodiment of the invention has been shown and described herein, it is obvious that various changes may be made without departing from the spirit of the invention or the scope of the annexed claims.

I claim:

1. Apparatus for use in the multiple stage oementing of casing in wells comprising an elongated collar adapted to be made up with the casing and having one or more ports therein for the discharge of cement slurry therethrough, a differential valve arrangement mounted in said collar and consisting of two sleeves mounted one above the other for sliding movement within said collar for controlling the flow of iluid through said ports, means for holding, temporarily, each of said sleeves against sliding movement in said collar with one of said sleeves covering said ports, and means operable by the passage of objects successively down through the casing for releasing successively the means holding said sleeves against sliding movement and for causing said sleeves to uncover said ports and subsequently again cover said ports, the upper of said sleeves having a portion of the same outer diameter as the lower of said sleeves, and another portion adapted to telescope snugly within the lower of said 'sleeves thereby providing areas on said sleeves subjected to different total iluid pressures tending to cause said sleeves to telescope.

2, Apparatus for use in the multiple stage oementing of casing in wells comprising an elongated collar adapted to be made up with the casing and having one or more ports therein for the discharge of cement slurry therethrough, a diiierential valve arrangement mounted in said collar and consisting of two sleeves mounted one above the other for sliding movement within adapted to telescope snugly within the lower of said sleeves, means for holding, temporarily, each of said sleeves against sliding movement in said collar with the lower of said sleeves covering said ports, and means operable by the passage of objects successively down through the casing for releasing successively the means holding said sleeves against sliding movement Land for causing a sequence of operation in which the lower sleeve moves down to uncover said ports to permit the fiow of uid therethrough and then the upper sleeve moves down to cause the skirt thereof to telescope within and maintain a seal with said lower sleeve thus covering said ports and preventing the flow of iuid therethrough.

3. Apparatus for use in the multiple stage oementing of casing in Wells comprising an elongated collar adapted to be made up with the casing and having one or more ports therein for the discharge of cement slurry therethrough, a diiierential valve arrangement for controlling the ow of fluid through said ports first to prevent such ow, then permit a limited amount of iiuid to ilow and then to prevent such flow permanently in response to the passage of objects successively down through the casing, said differential valve arrangement including a lower sleeve and an upper sleeve slidably mounted within said collar, said lower sleeve normally covering said ports, said lower sleeve having two packing rings on the outside thereof, one above and one below said ports when said lower sleeve is in its normal position, said lower sleeve also having a packing ring on the inside thereof near its upper edge, said upper sleeve having a portion of the same outside diameter as said lower sleeve, said portion having a packing ring on the outside thereof and said upper sleeve having a skirt depending from said portion and adapted to telescope snugly within said lower sleeve to effect a seal in the packing inside said lower sleeve.

CHARLES A. PITTS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,941,406 Manning Dec. 26, 1933 1,941,443 Manning Jan. 23, 1934 2,155,609 McClendon et al. Apr. 25, 1939 2,315,931 Burt et al. Apr. 6, 1943 2,379,079 Hayward June 26, 1945 

